Mechanical time fuse



at 12, 1948. J. J. HART 2,4;

MECHANICAL TIME FUSE Filed D60. 15, 1939 "Jar 5 m 1 Patented Oct. 12,1948 lTED ST TENT OFFICE 2,450,894 MECHANICAL TIME FUSE John J. Hart,Bryn Mawr, Pa., assignor to the United States of America as representedby the Secretary of War (Granted under the act of March 3, 1883, as

' amended April 30, 1928; 370 O. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to mechanism for releasing the timing disk in amechanical time fuse from the setting capafter the fuse has been set andat the time a projectile is fired armed with the fuse.

It is an object of the invention to generally simplify and provide arelease mechanism more positive in its action than release mechanismsused for such function heretofore in the art.

It is a further object of this invention to provide a timing diskrelease mechanism operable to release the timing disk by the same forcethat operates to drive the timing disk whereby release of the timingdisk and initiation of the driving thereof will be coordinated in pointof time.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is a plan view of the release mechanism of this invention lookingfrom the bottom of the setting cap;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1;

Fig. 3 is a sectional view similar to Fig; 2 showing the releasemechanism in interlocked relation with the setting cap and timing diskfor setting the fuse.

Referring now to the drawings wherein similar elements are identified bysimilar characters throughout, there is shown in Fig. 2 a fragmentaryportion of a fuse sufficient to disclose the present invention. The fuseportion shown comprises a setting cap I which is secured to and isrelatively rotatable with respect to the base of the fuse and clockworktrain II. As clearly understood in the art the timing disk I2 is securedto the clockwork train through the spindle I3 and friction disk It inorder that the timing disk may be rotated on the spindle I3independently of the clockwork train to position the release shaft slotI5 in the timing disk in any predetermined position of rotatabledisplacement from the release shaft.

For rotating the timing disk I2 to position the release shaft slot I5therein a desired distance from the release shaft to correspond with aiven setting of the fuse it is usual to employ the setting cap ID forsuch purpose and in the instant invention a cantilever setting spring I6secured at one of its ends by fastening means I! to the setting cap andhaving a setting lug I8 in its free end provided with a dependingprojection I9 adapted to engage in a cooperatin perforation inthe-timing disk is provided. The setting lug I8 above the upper surfaceof the setting spring is provided with an inclined surface 20 and acentrifugal spring 2I secured to the setting cap at one end, as at 22,is arranged to have its free end portion engage the inclined surface 20of the setting lug I8 and cam the setting spring I6 down with thedepending projection is engaged Within the cooperating perforation inthe timing disk as shown in Fig. 2.

Conveniently the centrifugal spring 2! may be a wire spring with its end22 formed in a single coil to provide an eye for the cooperating meansemployed to secure the spring to the setting cap. The freeend of thespring is likewise coiled to form an eye within which is secured acentrifugal weight 23.

In the operation of the release mechanism of this invention the partswill normally be disposed as shown in Fig, 2 during the static conditionof the fuse. In this position the cantilever setting spring I6 isdepressed by interengagement of the centrifugal spring 26 and inclinedor beveled surface 20 of setting lug I8 and projection I9 is engagedwithin the perforation therefor in timing disk I2. When it i desired toset the fuse the cap I I! is rotated a predetermined distancecorresponding to the setting desired and this movement of the settingcap transmitted through the attached setting spring I6, lug I8 andprojection I9 will rotate the timing disk I2 on the spindle I3 againstthe friction imposed by the friction disk I l to displace the releaseshaft slot I5 the required distance from the release shaft.

After the fuse is set and when it is fired from a gun attached to aprojectile the rotation imparted to the projectile will developcentrifugal to be driven by the clockwork train through the spindle I3and friction disk I l and will be driven through a distancecorresponding to the timefor which the fuse is set whereupon the releaseshaft slot IE will be brought to a position where the release shaft mayenter the same and. release the firing pin to ignite the detonatin trainof the fuse.

Having now described what is at present a preferredaembodiment' of theinvention l claim and desire to secure by U. S. Letters Patent:

1; In a fuse of the type having a timing disk.

in combination, a setting cap for enclosing the timing disk and.rotatable relative thereto, a" setting spring secured to thewsettingcaphaving a free end. portion provided. with: means ada-pted to beinterlocked with the timing disk upon depression of the setting spring,and. spring means secured to said setting cap normally depressingthesetting spring, said last named means-being operable by centrifugalforce to release the setting spring from its depressed position.

2. In a fuse of the type having a timing disk in combination, a settingcap for enclosing the timing disk and rotatable re-Iati've thereto, acantiil'ever 'setting-ispring secured to-the "setting" cap, asettinglug: having a beveled upper surface and depending projection secured tothe free end of the setting spring, said depending projection adapted tobe interlocked With the timing disk upon depression of the settingspring, a centrifugal spring provided with a weight on one end securedto thesetting cap through its end remote from the weight and beingbiased to normally en- ?gage the beveled surface of the setting lugadj'acent its weighted end portion to depres the setting spring withsaid projection interlocked with. thetiming disk,. said weighted endportion of the centrifugal spring being operable by centrituga-l forceto Ice-disengaged from the beveled surface of the setting lug. p

JOHN J. HART.

REFERENCES CITED The following references are of record in the file ofthis patent:

FOREIGN PATENTS Number Eoun-try' Date Great Britain 1932-3

